Wildlife Promise » marine wildlifehttp://blog.nwf.org
The National Wildlife Federation's blogTue, 31 Mar 2015 15:26:11 +0000en-UShourly1http://wordpress.org/?v=3.9.2Beyond Fireflies: Bioluminescent Organismshttp://blog.nwf.org/2014/08/beyond-fireflies-bioluminescent-organisms/
http://blog.nwf.org/2014/08/beyond-fireflies-bioluminescent-organisms/#commentsSat, 09 Aug 2014 18:30:43 +0000http://blog.nwf.org/?p=99067Read more >]]>When it comes to bioluminescence, the first organism we typically think of would be the all-familiar firefly (also known as lightning bug). As land animals, fireflies are our most noticeable exposure to the reaction in which chemical energy is converted to light. But did you know that terrestrial bioluminescence is actually pretty rare and it occurs most frequently in marine wildlife? It’s true! Down in the depths of the ocean, light is scarce and bioluminescence can have multiple functions. According to the National Ocean Service, it can be used to warn or evade predators, to lure or detect prey, or to communicate with members of the same species.

I recently came upon this fascinating infographic that illuminates (haha!) all the different organisms that are bioluminescent. It’s a beautiful representation of how widely occurring bioluminescence is across land and sea. Make sure to click on the infographic to view a larger version.

We’ve also seen some real-life examples caught on camera and submitted to our annual National Wildlife Photo Contest. Have you witnessed bioluminescence in person? We’d love to know – make sure to share in the comments!

]]>http://blog.nwf.org/2012/08/photo-of-the-day-beautiful-but-deadly/feed/0June Ocean Wildlife Roundup: Shark Chomps Giant Squid, Seals on Camera, Cuttlefish in Troublehttp://blog.nwf.org/2012/06/june-ocean-wildlife-roundup-shark-chomps-giant-squid-seals-on-camera-cuttlefish-in-trouble/
http://blog.nwf.org/2012/06/june-ocean-wildlife-roundup-shark-chomps-giant-squid-seals-on-camera-cuttlefish-in-trouble/#commentsWed, 27 Jun 2012 14:41:46 +0000http://blog.nwf.org/?p=60631Read more >]]>We spend lots of time on Wildlife Promise talking to you about amazing animals in the U.S. and elsewhere. But in my opinion, we don’t use nearly enough digital ink on marine life. I hope we can remedy that in part by putting out a monthly blog digest featuring a few odd or important news items about ocean creatures of all types.Enjoy, and please let me know what I missed.

Australia’s Giant Cuttlefish in Trouble as Weak Spawning Season Continues

Australian giant cuttlefish may be in trouble, as evidenced by low summer spawning numbers (flickr| richard ling)

The rocky coastline of the Upper Spencer Gulf in South Australia is the only place in the world where the Australian Giant Cuttlefish spawn in large numbers, and it has become a popular spot for scientists and cephalopod-loving weirdoes like me each year.

Researchers say the low numbers are cause for concern, and they don’t yet know what’s causing the trend (though “BHP Billiton’s proposed desalination plant” nearby probably won’t help. It would reportedly pour “huge quantities of hypersaline wastewater” into Spencer Gulf and make the area unpalatable for a variety of species). A new study finds that the cuttlefish breeding colony had decreased by 78% in the past decade, and last year marked a record low.

The image rehabilitation plan comes as local fishermen ramp up claims that the seals have been depleting area fish stocks. Recent cases of people pestering—and in some cases killing—the seals have come partly as a reaction to these rumors, and spurred scientists to “glue submersible cameras onto the seals’ backs, using the footage to prove to fishermen the animals are not harming their way of life.”

Video: Blue Shark Chomps Giant Squid

Giant squid are mysterious, awesome and locked in an eternal arms race with sperm whales. Live sightings are so rare that even footage of a recently dead Architeuthis is a pretty big deal. Recently, Australian angler and journalist Al McGlashan came across a largely-intact carcass whose bright red coloration indicated it had died recently. While he filmed, a blue shark tore into the squid, thus launching the best cephalopod viral phenomenon of 2012 (so far…I eagerly await your videos of octopuses singing ‘Call Me, Maybe’). Take a look at Field & Stream’s exclusive full-length video and photos right this second.

Canadian Lobster is Blue, Yet in Decent Spirits

Canadian lobster boat captain Bobby Stoddard caught a lobster in early May that resembled a giant Avatar cat person. That’s the way we say ‘it was blue’ in America now.

Blue lobsters do occur, but they’re uncommon. According to The University of Maine’s Lobster Institute, “only an estimated one in two million lobsters is blue” (which makes them rare, but not quite as rare as live, naturally red or yellow lobsters, which are estimated at one in ten million and one in 30 million, respectively). Blue lobsters come about due to “a genetic defect that causes the lobster to produce an excessive amount of a particular protein.”

Manta Ray Ultrasound Sheds Light on Liquid Oxygen Intake

A study recently published in Biology Letters is the first to show how manta ray embryos get oxygen, based on video from an ultrasound performed on a pregnant ray in 2008.

Though manta rays, like many other cartilaginous fish, give birth to live young, they lack an oxygen-giving umbilical cord or placenta. According to researchers, “the baby ray was raising and lowering its jaw, pumping uterine fluid in through its mouth and spiracle.” The continuous regulated flow of the fluid over the ray’s gills allowed the embryo to extract oxygen (the baby was “a healthy female, 2 meters from wingtip to wingtip and weighing 50 kilograms” at birth). According to Taketeru Tomita, a fish biologist at Hokkaido University Museum, this is the first time that scientists have observed fetal viviparious vertebrates pumping liquid to extract oxygen.

Great Whites Summering in Cape Cod

Researchers tag a shark near Chatham, MA, in 2009. Tagged great whites recently returned to Cape Cod to feed on seals. (flickr | Massachusetts Energy and Environmental Affairs)

Researchers say the sharks were drawn to the area by “a growing seal population on Monomoy Island,” redoubt of migrating birds and other non-humans for hundreds of years. They haven’t come close enough to tourist beaches to warrant any official warning, though mayhem will presumably occur if the star-crossed Brody family gets too close.

If you’ve seen a story that you think should be covered in the next Ocean Wildlife Roundup, please let me know in the comments below, email me at greenbergm@nwf.org, or tell me on Twitter @MaxTGreenberg.

But if you consider pelagic sargassum, that yellowish-brown seaweed that forms up into floating mats, clumps and weed lines (scientists call them “weedrows”), you will find entire habitats destroyed by the Gulf oil disaster.

“We’ve actually identifiedover 130 species of fish that utilize sargassum as habitat at one life stage or another,” he explained.

Researchers Surveying Sargassum

Though it looks like a floating carpet, sargassum grows to three feet deep. Photo: Belinda Serata/NWF

From 2000 to 2004 a team of GCRL scientists, including Dr. Eric Hoffmayer, also of GCRL, and Franks, have studied sargassum.

Team members made 14 sampling cruises in the north central Gulf of Mexico. They used large- and small-mesh nets to target juvenile fish and larvae, and collected samples by towing nets through, adjacent to and below sargassum to a depth of 50 meters.

The final tally of fish that used sargassum as habitat during the sampling cruises came to 110 species, a slight under count because 19 fish could be ranked only by family, not by genus and species.

It’s interesting to note that these surveys specifically targeted juvenile and larval fish. Other animals were collected but no crabs, shrimp or other animals that depend on sargassum were counted. A less scientific, but perhaps equally enlightening experience is to jump into the water near a sargassum mat or, as our lawyers would prefer I recommend, view the habitat from a boat.

In the sky, watch for the masked booby, red-necked phalarope and various terns and gulls. The bridled tern often rests on top of the clumps of sargassum.

Sargassum and the Oil Spill

Sargassum is habitat. And a lot of it was wiped out by oil, dispersant and burning. What no one can tell me is how much animal and plant life was destroyed either by oil, chemicals or fire.

“I saw a considerable amount of sargassum that was actually in the oil and in the dispersed oil and in the oil sheens,” said Franks. “We saw a lot of that in our offshore cruise in May. At that point we were about 80 miles south and looping around to 80 miles north of the actual spill site, so we were some distance away,” he added.

Asked how many fish, shrimp or crab larvae or juveniles were killed in oiled sargassum Franks said, “There’s no way to tell for sure. It’s something we plan to investigate,” he added.

And therein lies the rub. There are very good measurements of very small pieces of the puzzle. After that, it’s a matter of mathematical models, extrapolations and guesswork.

Sea Turtles in Need of Sargassum

Take turtles, for instance. We know that several species of hatchling sea turtles make their way to sargassum mats and live the early part of their lives within those weeds.

So how much oil hit how much sargassum? How many of each turtle species were there when the oil hit? What were the effects of the oil on sargassum and baby turtles? How many turtles were harmed or killed and how many made it through ok?

A 2008 study by the Florida Fish and Wildlife Research Institute surveyed sargassum habitats for neonate (i.e., hatchling) sea turtles. The study found 60 sea turtles per square kilometer of sargassum habitat (30 green turtles and 30 Kemp’s Ridleys) in one survey area off Pensacola, the smallest of six survey areas around Florida (four in the Gulf, two in the Atlantic).

So all you have to do is figure out how much sargassum is out there, and how much of it was hit by oil and chemical dispersants, and you can generate at least an estimate of the number of baby green and Kemp’s Ridley sea turtles that were impacted by the Gulf oil disaster — maybe even stretch to say “harmed” by oil and chemicals.

That’s what the Natural Resource Damage Assessment (NRDA) is trying to figure out. And it’s not just about the nature. It’s about money — fines and penalties and lawsuits. Which means the lawyers should do just fine.

But the sargassum is gone — destroyed and sunk to the Gulf floor. And with it, the habitat for baby sea turtles and a myriad of other marine newborns.